Lens mount



NDV. 18, 1941. D L, woop 2,263,024

LENS MOUNT Filed April 27, 1940 gl l A TI'ORNE YS to lthose in the' art. 'though unsatisfactory, has been extensively used Patented Nov/ 18, 1941 'UNITED f s'm'rlzs;v PATl-:N

sesam T OFFICE -LnNs Mom Domien wood. Rochester. my., einer to Eastman Kodak Company. Bnchester, N. Y., av Y corporation of New Jersey .l

Application spru 2 1, mesma No. :32,036 s chime (cuss-'41)' scale on the regular objective is no longer correct the attachment in place. When such at,

with

tachmentsare used, focusing is usually secured by adjusting the front-lens element only of ,the attachment, the other lens element of the attachment as wellas the lens elements of the 0bjective remaining stationary.V With suchr a method of focusing, the spacing of the lens ele'- ments of the attachments is varied, thus caus- 1 attachment constructed ig. 2 lis a perspective view of aCine 'objective lens of vwell-knownI con struction;.l

Fig. 3 is a side view of a supplementarylens Fig. 14 is a side view of the 'objective .lens as v vshown in Fig. 2 with a supplementary 4lens .def

ing distortion and other aberrations well known This method of focusing, al-

because it was simple, and because no other practical method was known.

The present invention has as its principal object, the provision of an arrangement by whichl focusing is secured without any variationin the spacing4 of the various lens elements of the suplens attachment. Another object cf the invention is the provision of an arrangement by wbichthe moving means of the objective lens element is renderedterially changing the spacing thereof.

Still `another object of the invention is the provision of a supplementary lens attachment which is provided with a suitable scale, which,

when the' attachment issecured to the camera invention is ,the pro-.-

A rui-ther obieetlof the a`fccu'sing scale is in deaigm'inmensiveto manufacture,

tachably secured in position'thereon;

Fig. 5 is a view similar'to Fig. 4,'but on a larger scale than the latter, with parts insec.-

tion to show the. methodoi maintaining the attachment on the objective-and `for securing the focusing adJustment;

Fig. Gis aview similar to Fig. 5 but showing a l modiiied arrangement of a focusing scale onthe supplementary lens attachment; and- FigQI is a fragmentary end view of' the focus'A ingscale ring illustrated in Fig. 6,'and showing the arrangement by which the' scale'ring, and hence` the supplementary -lens attachment, may

. be detachably secured tothe'objegtive ma lrel axially along the tube elements il and' .il without "17mg thespacing Similar reference numerals thrcugh.the.vgr.

ious views indicate the sameparts. i The drawing shows a Cine obiective lens mount il of any` suitable and well-knowncon'- -struction which comprises-an outer cylindrical tube Il adapted to be attached to a inl a well-known manner. A lens barrel i! is nonrotatably but axially movable in the tube il and carries a pair of spaced lens elements Il-fand Il which are fixed in position on the lens barrel.. :A

lfocusing ring il is 'rotatably mounted on the tube il and is connected tothe barrel l2, inanw suitable -and well-known manner, so that thev rotation of lthe ring serves -move the lens bartherebetween, vall of whichis well known tothose inthe art.4

The lens barrel extending slot It arranged to. receive a tongue i1 secured to a sleeve il of a masking'device Il todetachabiysecurethelatte'rwthefrontof the lons barrel. The front of the masking device is formed with a rectangular masking aperture. not-shown. When the'ms'sking device is in position, the sleeve Il' is slid into andeng'ag'es the tive mount.l The objective lens mount-,with the masking devies, may be o f any standard'oi' well-known eonstmction anddossnotperssconstituteapartoitheprs- JA furtherdetailed discussion is,

in accordance with the- I'tofocusthelens lz is formed with an therefore, not deemed necessary for those in the art to fully understand the present invention.

A supplementary lens attachment, generally indicated by the numeral 25 and of the shape best shown in Fig. 5, is adapted to be detachably secured to the objective mount Il) in a manner to be later described. This attachment is tubular in shape and comprises a cylindrical front end portion 25 in which is mounted the front lens element 21, an. intermediate portion 28, and a rear portion 29 which is shaped to conform with and to preferably frictionally engage the inner surface of the llens barrel I2, as clearly shown in Fig. 5. This rear portion 29 has mounted therein a rear lens element 3|. ments 21 and 3I are thus fixed in spaced relation in the attachment 25, the purpose of which construction will be later pointed'out. 'I'he rear end of the intermediate portion 29 is formed with a circumferential groove or slot 32 adapted to receive the front end 33 of the lens barrel, as clearly shown in Fig. 5. A rearwardly extending tongue 34 is secured to the outer .surface of the portion 29 by rivets 35, or other suitable fastening means.

' In assembling the attachment, the tongue 3 4 f thereof is first brought into registry with the slot I6, and the attachment andthe objective III arel then moved axially toward each other to position the tongue in the slot and to slide vthe rear portion 29 of' the attachment into the front end of the lens barrel, as will be apparent from an inspection. of Figs. 4 and 5. When the attachment is in proper position, the spring 25 in the lens barrel then registers with and automatically snaps into a groove 35 formed inthe attachment,

-as shown in Fig. 5, to positively connect the atresult in focusing by the lens separation of the lens elements of the Supplementary lens attachment.

When the objective I alone is used, the desiredl focusing is seemed by rotatingthe focusing ring- I to bring the desired portions of the scale 40-thereon into alignment with a fixed pointer 4I formed on a stationary ring 43 suitably secured to the tube II, as is well. known. As the scale is, of course, designed only for the lenses I3 and-I4, obviously this scale is no longer correct for one resulting focal length when the attachment 25 is in position, as shown in Figs. 4, 5, and 6. Obviously; therefore, a new focusing scale must be provided for the .combined lens elements of the objective I0 and the attachment 25. If only a single attachment is to be used, a second auxiliary scale could be provided on the objective itself, this second scale being employed only when the attachment 25 is utilized. However, such a double scaleon the objective would be undesirable, for obvious reasons. Furthermore if a number of different attachments were used, a separate scale` would be required for each attachment. Such a multiplicity of auxiliary scales would certainly tend to' lead to confusion onthe part of the user.

The lens elevprovided for each attachment, each scale being,

of course, `designed for the combined lens system of the particular attachment 25 and the objective I0. By means of 'this arrangement, a large number of separate attachments may be selectively and interchangeably used with the camera objective I0. As mentioned above, rotation of the ring I5 moves the lens barrel I2 and the attachment 25 as a unit to secure the focusing. Such rotation of the ring serves to move the pointer 44 thereon over the non-rotatable but axially movable scale 42 on the attachment to indicate the proper focusing adjustment.

It is apparent from an inspection of Fig. 4, that when the attachment 25 is connected to the'objective I5, both the focusing scales 40 and 42 are visible.V Obviously when the attachment is in place, focusing is accomplished by means of the latter scale only. However, in order to eliminate any chance of error, the present invention also provides a modified arrangement by which a scale 40 of the objective III is' completely covered when Y' theattachxnent 25 is connected thereto so that only the correct .focusing scale will be visible.

. This modified structure is shown in Figs. 6 and 7. Parts corresponding to those in Figs. 1 to 5 will4 be designated by the same numerals. In order to cover the objective focusing scale 40, the attachment 25 has permanently secured to the shown in Fig. 6.

.outer surface thereof at 50, a cylindrical scalev Y sleeve 5I which overlies and is spaced from the intermediate and rear portions 28 and 29 of the 1 attachment 25, as clearly shown in Fig. 6. When the attachment is secured to the objective III, the

sleeve 5I extends over and completely covers the focusing ring I5 and the scale 40 and has the end 52 thereof terminating adjacent the stationary ring 43 winch carries the fixed pointer, as 'I'his sleeve 5I has suitably formed thereon a focusing scale 53 which is adapted to cooperate with the fixed pointer 4I in a manner to be later described. It is to be understoodthat the scale 53 is designed for the combined lens system of the objective and the attachment, and not merely for the latter, so that by bringing the proper indication of the scale 53 into registry with the pointer 4I, the complete mount will be in proper focus.

As the 4sleeve 5I covers the focusing ring I5, obviously the latter-cannot now be directly rotated to focus the mount. ,In this embodiment, the sleeve 5I is utilized to impart the necessary rotative movement to the ring I5. To secure this result, the inner surface 54 of the sleeve 5I is formed with a plurality of -longitudinally extending lugs or ridges 55 which are adapted to engage and cooperate with similarly shaped knurlings 55 formed on the outer surface of the ring I5, see- Fig. 4. By means of this arrangement, a spline connection is provided between the sleeve 5I and thering I5. This connection not only permits the sleeve 5I to be slid into overlying position on the ring I but also imparts the necessary turning movement -to the ring I5 xupon' rotation of the sleeve 52. When the latter is slid into position, it is imperative that the scale 52 thereon be in proper relation to the scale'll of 'the objective III, as will be apparent to thosein the art.v

To this end, the present invention provides an I arrangement by which the sleeve II can only be g mounted when the infinity reading of the scale- 53 is in alignment with. the infinity reading of the scale 40. To secure this result, the sleeve 5I has a portion 51 in which the lugs 55 are omitted to engage a similarly smooth portion, not shown, on the focusing ring. By means of this simple arrangement, proper positioning of the sleeve 5I, and hence the focusing scale 53 is positively insured. In order to retain the scale I3 in proper axial position on the ring I5 the sleeve 5I is provided with pairs of axially extending slits 58 which provide flexible fingers 59 each of which is formed with a depending protuberance GII adapted to spring over and snap into recesses or grooves 6I formed on the periphery of the ring I5, as clearly shown in Fig. 6. y

It is apparent that due to the spline connection 55 and .56,Yany rotation of the scale sleeve 5I will also rotate the focusing ring I5 to nonrotatablyl move the lens barrel I2 axially ofthe tube II, as pointed out above. However, as the sleeve 5I is connected at 5I) to the attachment 25, the latter will also be rotated as a unit therewith. It is well known, however, that due to the threaded engagement of` the focusing ring I5 with the tube II, any rotation of the ring will also cause the latter to move axially relative to the tube II. This axial movement of the ring I5 will, through the connections 50 and 5I, impart the required axial movement to the attachment 25, and will also move the latter axially relative to the lens barrel. This relative axial ment, a plurality ofv lens elements arranged in movement between the lens barrel and the atis quite small and is not detrimental, as will be apparent to those in the art. The important point is, that'focusing is secured without changing the spacing between the lenses 21 and 3| of the attachment 25, thus effectively overcoming the undesirable results secured in the prior method of focusing in which relative axial movement between the lenses of the attachment was necessary to secure the desired focusing adjustment. As. the attachment 25 is both rotated and moved axiallyrelative to the lens barrel I2, the connectingy tongue 34 and the spring receiving groove 35 are omitted in this modiied embodiment illustrated in Figs. 6 and '1. In addition, the diameter of the rear portion 29 of the attachment 25 is preferably made slightly smaller so as to aflord a slight clearance between the portion 29 and the lens barrel I2, as clearly shown in Fig. 6.

As the sleeve 5I is thus rotated, the scale I3 thereon will lmove over the iixed pointer 4I to clearly indicate the focusing adjustment of the entire mount. However, as thel sleeve, II completely covers'the scale l0, the possibility of using'thewrong'focosinirscaleistherebyellin-A imted, the advantages of which will be readily apparent. When, however, the attachment 2l isremovedthesleevsll isremovedas-aunit mutandine-ablesen ioeuiimwus un. 'alain uncovered and is rmdered 4 eifective for focadngthelenses Itand Iloftheobjective Il.

Itis thus apparent from the above description that the present invention provides an arrangement for focusing without any separation of the lens elements of the supplementary lens attachment. It is also apparent that the attachment is so connected to the lens barrel of the objective that the various lens elements are simultaneously moved to secure the n focusing adjustment. In addition, the auxiliary focusing scales are carried by the separate attachments so that a wide range of attachments may be selectively used with the regular objective lens mount.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive id'ea may be carried out in a number of ways. This application is, therefore, not to .be limited to the precise details described, but is intended to cover all variations and modications thereof fallingwithin the scope of the appended claims.

Iclaim: .Y

1. In a lens mount, the combination with a camera objective, a lens barrel formed with an axially extending slot, a plurality of lens elements mounted in proper spaced relation in said barrel, means for moving said barrel axially of said objective, of a supplementary lens attachfixed spaced relation in said attachment, and an axially extending tongue on said attachment arranged to be positioned in said slot to connect said attachment to' said barrel so that axial movement of the latter will simultaneously move said attachment as a unit therewith to focus said mount without altering the spacing of said lens elements.

2. In a lens mount, the combination with a camera objective, a lens barrel mounted for axial movement in said objective and formed with an axially extending slot, a plurality of lens elements mounted in xed spaced relation in said barrel. a focusing ring rotatably mounted on said objective and operatively connected to said .barrel for moving the latter axially of said objective, of a supplementary lens attachment, a plurality` of lens elements arranged in fixed spaced'rela-4 tion in said attachment, a tubular portion on said attachment arranged to be slid into said barrel, a tongue on said portion arranged to engage said slot to detachably connect said attachment to said barrel and to position said second lens elements relative to said first lens elements so that said barreland attachment may be noved axially. as a unit -upon rotation of said ring without varying the spacings between any of said elements, and means on said barrel arranged to engage a complementary section of vsaid portion to retain the latter in position in said barrel. I

3. In a lens mount, the combination with a camera objective, a lens barrel mounted for axial movement in said objective and formed `with an axially extending slot, a plurality of lens elementsv mounted in fixed spaced relation in-said barrel, a focusing ring rotatabiy'mounted on said objective and operatively connected to said barrel for moving the latter axially of said objective, of a supplementary lens attachment,r a plurality of lens elements arranged in nxed spacedreiationinsaidattachmsntasleevesecuredtoand movable as a unit with said attachment and operativelyconnecd tosaid'ringsothatrotaon elements, and means for palm and detachably connecting said sleeve on said ring.

4. In a lens mount, the combination with a camera objective, a plurality of'lens elements arranged in ilxed spaced relation in said objective, means for moving-said elements as a unit axially of said objective, of a supplementary lens attachment, a plurality ofl lens elements arranged vin fixed spaced relation in said attachment, co-

5. In a lens mount, the combination with a camera objective, a lens barrel mounted for axial movement in said objective, a plurality of lens elements arranged in fixed spaced relation in said barrel, means operatively connected to said barrel pointer carried by said barrel moving means and positioned adjacent and cooperating with said scale to aiord a focusing means for said mount.

7. In a lens mount, the combination with a camera objective, a lens barrel mounted for axial movement in saidobjective and formed with an axially extending slot, a plurality of lens elements mounted in iixed spaced relation in said barrel, a focusing ring rotatably mounted on said objective and operatively connected to said barrel for moving the latter axially of said objective, of a supplementary ylens attachment, a plurality of lens elements arranged in iixed spaced relation in said attachment, a sleeve secured to and movable as a unit with said attachment and operatively connected to said ring so that rotation for moving the latter axially of said objective, of l a supplementary lens attachment having a portion thereof positioned in said barrel, a plurality of lens velements arranged in fixed spaced relation in said attachment, means for operatively connecting said attachment to said barrel moving means so that actuation of said moving means will serve to simultaneously move said attachment axially to focus said mount without changing the spacing of said last mentioned elei ments mounted in proper spaced relation in said" barrel, means for movingA said barrel axially of said objective, of a supplementary lens attachment, a plurality of lens elements arranged in xed spaced relation in saidattachment, an axially extending tongue on said attachment arranged to be positioned in said slot to connect said attachment to said barrel so that axial movement of the latter will simultaneously move said attachment as a unit therewith to focus said mount without altering the spacing of said lens elements, an axially movable but non-rotatable scale carried by said attachment, and a rotatable of said sleeve will simultaneously move said barrel and said attachment axially to focus said mount without varying the spacings of said last mentioned elements, means for positioning and detachably connecting said sleeve on said ring, a movable scale element carried by said sleeve, and a stationary pointer carried by said objective and cooperating with said movable scale to afford a focusing means for said mount. i

8. In a lens mount, the-combination with a camera objective, a lens barrel mounted for axial movement in said objective, a plurality ofv objective lens elements arranged in xed spaced relation in said barrel, a focusing ring carried by said objective and operatively connected to said lens barrel and adapted to move the latter axially of said objective upon actuation of said ring to focus said elements, an objective focusing scale carried by said ring, a pointer carried by said objective and adapted to cooperate with said scale to indicate the focusing adjustment of saidelements, of a'supplementary lens attachment adapted to be detachably secured to said objecc is secured to said objective, an auxiliary focusing scale vcarried by said sleeve and arranged to cooperate with said pointer to indicate the focusingadjustment of said objective and supplementaryv elements, and cooperating means on said sleeve and said ring for `connecting said sleeve to said ring s'o that rotation of said sleeve will actuate said ring to simultaneously move said attachment and said barrel axially of said objective to focus said elements without any change in the spacing of said supplementary elements. I

DONALD L. WDOD. 

